Pilot-valve.



En V. ANDERSON.

PILOT VALVE.

APPLICATION PILPD 0011s, 1911.

1,092,80, Patented 11pm, 1914 INVENTOR,

WITNESS ESI 4 EDWARD V. ANDERSON, 0F MONESSON, PENNSYLVANIA, ASSIGNOR OFONE-HALF TO CHARLES E. GOLDEN,

lOIE GRAFTON, PENNSYLVANIA.

PILOT-VALVE.

1, tij 2,

Patented apr. a, mia.

To all whom it may concern.'

Be it known that I, EDWARD V. ANDERSON, a citizen of the United States,residing at Monesson, in the State of Pennsylvania, have inventedcertain new and useful Improvements in Pilot-Valves, of which thefollowin is a specification.

iy invention relates to valves used for the purpose of handling'otherand larger valves, and its primary object is to provide a device whichautomatically` opens and exhausts the pressure of other apparatus whenabnormal conditions occur, being particularly designed as a safetydevice to close otf the boiler pressure from a steam header when thelatter develops a break or leak.

I have illustrated the invention in the form of a pilot valve forgoverning another and larger valve which is operated by exhausting thepressure, in any of the well known ways.'

Figure 1 is a vertical cross-section of the differential pilot valve andFig. 2 shows its application tothe government of what is commonly calleda triple-valve, used in steam lines. s

There are in use many forms of valves which are opened or closed bytheopening of an exhaust port .when certain' desired conditions arise inthe relation between pressures on the two sides of the valves. It makesno difference to my invention what may be the object of relievingYt-hepressure.

The invention resides in the provision of an automatic and adjustabledifferential pilot valve, whose function is to exhaust the pressure fromanother device under certain previously determined conditions. Forexample, I have shown in Fig. 2 a main valve 3 which leads from a pipe4a from the boiler to a pipe 5a going tothe steam line, :and this mainvalve is operated for certain purposes by exhausting pressure from somepart of its chambers by means of a pipe 6a having a final outlet at 7.

8 represents the casing of a pilot valve for controlling this outlet andit is shown in detail in Fig. 1.

In Fig. 1, the casing 8 contains an operating piston 9 having a leakagearound it, and in turn moving a valve 10 which opens a port 6 tocommunicate with an exhaust port 7. In the casing above the piston 9 isset a diaphragm 11 having a port l2 governed by a valve 13. This valve13 is held loosely hollow and contains as by a screw ring, on the bottomof a plunger whose head 14 is attached to a flexible diaphragm l5 whichdivides the chamber A into two parts. The piston 14'* is va spring 16which is of a traveling head 17 carrled on a screw 18 in the top of thevalve casing 8. On the upper side of the diaphragm 15, the portk 5connects with the pipe 5b shown in Fig. 2, coming from the steam main;and on the underside of the diaphragm l5 a port 4 connects with the pipe4b in Fig. 2 coming from the boiler.

It will be seen that the small valve 13 is normally closed under thepressure of the spring 16 and the pressure from the port 5, and partcounterbalanced by pressure adjustable by means sure and t-he pressurein the main reaches a desired limit, (adjustable by means of the screw18), the small valve 13 will be opened and the boiler pressure escapingthrough port 12 will act on the piston 9 and open the valve 10, allowingescape of pressure from the triple-valve by way of the pipe ea, eb.`

This pilot valve can convenient point and can be adjusted at will andgives avery eiiicient governor for any other valve actingby escape ofpressure. The advantages of the device will be obvious to those familiarwith the art. For exbe located at any p ample an opening of the valve isindependent of the actual boiler pressure and of the actual fluctuationsin boiler pressure, being operated only by a predetermined difference ofpressure between the boiler and the main. And, moreover, this limitingdifference of pressure may be actually adjusted.

Having thus described my invention and its use, .what I claim is t-hefollowing:

1. An automatic pilot valve for main steam valves comprising a casinghaving a normally closed exhaust port, a device to open said exhaustport by admission of igh pressure from the steam main and means toprevent said admission of high pressure controlled by the difference ofpressure between the inlet and outlet sides of the main steam valve.`

2. An automatic differential pilot valve, comprising a. casing having anexhaust passage adapted to be connected for operating another valve, avalve in said passage, a.'

g f y 1,092,806

piston chamber and a piston therein connected with the stem of thevalve, a dia.- phragm chamber and a diaphragm dividm 1t, a port betweenthe piston chamber an the underside of the diaphragm chamber2 a Ycheckvalve loosely carried all? said dla.-

phragm and adapted to norm close said port, ports on the respectivesides of the diaphragm adapted to connect the underside and theupperside of the diaphragm chamber, respectively to the high pressureand low pressure sides of the valve to be governed and a spring toregulate the movements of the diaphragm and therefore the admission ofhigh pressure to the valve oper- 15 ating piston, whereby said pistonoperates the valve toopen the exhaust when'a predetermined and regulabledifference occurs between the high pressure and low ressure sides of thevalve to be governed by t e pilot.

In testimony whereof I have hereunto signed my name in the presence ofthe two subscribed witnesses.

EDWARD V. ANDERSON.

Witnesses: FREDK. STAUB, Jo. BAiLY BROWN.

